What is the test for unanimous agreement on a jury's verdict in a murder trial?

Pursuant to this instruction, the jury was instructed: "You may consider these different kinds of homicide in whatever order you wish, but I can accept a verdict of guilty or not guilty of second degree murder only if all of you have found a defendant not guilty of first degree murder. [] As with all of the charges in this case, to return a verdict of guilty or not guilty on a count, you must all agree on that decision." The instruction then more specifically informed the jury regarding how to fill out the verdict forms. We conclude the jury would have understood from this instruction that it was required to unanimously agree as to the degree of murder. " 'A defendant challenging an instruction as being subject to erroneous interpretation by the jury must demonstrate a reasonable likelihood that the jury understood the instruction in the way asserted by the defendant. [Citations.]' [Citation.] 'We credit jurors with intelligence and common sense [citation] and do not assume that these virtues will abandon them when presented with a court's instructions. [Citations.]' [Citation.] ' "[T]he correctness of jury instructions is to be determined from the entire charge of the court, not from a consideration of parts of an instruction or from a particular instruction." [Citations.]' [Citation.]" (People v. Sanchez (2013) 221 Cal.App.4th 1012, 1024.)